Well, I suppose if it's dry enough, it could possibly be ok. But if it gets anywhere near any moisture, it seems a disaster waiting to happen. I wonder how they will keep the freehub moving - then again, there must be plenty of machinery kept working on the bases down there, even through the winter.

I've had my derailleurs freeze up, though it was the cabling rather than the der. themselves that was the problem. If the cable routing is internal it might work. Freezing your derriere is another matter...

The small-diameter tires seem like a strange choice. I'd think that they'd bog down in deep stuff because the angle of attack would be too great for them to climb out of it. I'd think that the Surly Moonlander-type approach would work better.

Yes, same here with the freezing cables, but others have reported the cassette block filling up with ice too. However, it seems that the Arctic is too dry for this. Reports indicate they have still barely used the bikes though, and had to push them for miles.